This invention relates to a paper sheet counting apparatus and more particularly to a stacker for such apparatus, by means of which paper sheets such as banknotes that are taken out of a hopper of the counting apparatus and counted by a counting mechanism are stacked in trim order through use of a rotary drum provided with blade members.
In such a stacker, the paper sheets taken out intermittently from the hopper are accommodated between adjoining blade members of the rotary drum rotated synchronously with an extracting roll so as to be sequentially stacked on the stacker. In the conventional stacker, the blade members are securely mounted to the drum, as disclosed for example in the Japanese Laid-open Utility Model Publication No. 81-122168, so that the gap between adjoining blade members has a constant magnitude at all times.
However, the paper sheets extracted intermittently by the extracting roll are subjected to slipping with respect to the surface of the extracting roll under various operating conditions. Therefore, the paper sheets are not necessarily maintained at equal intervals from one another when supplied to the rotary drum. Thus the paper sheets are not necessarily supplied to the gap between adjoining blade members, but may occasionally abut on the tip ends of the blade members, or the leading ends of the paper sheets may be acted upon by the trailing ends of the preceding sheets, to be accidentally ejected out of the stacker.
Such inconvenience might possibly be eliminated by enlarging the gap between the adjoining blade members and thereby the distance between the tip ends of these members, by enlarging the radial size of the drum and thereby increasing the circumferential size of the drum at the tip ends of the blade members. However, this is not fully satisfactory for obviating the above inconvenience, because reduced overall height and faster counting speed are always required of the paper sheet counting apparatus.